1. Field of the Invention
This invention relates to transfer switches and, more particularly, to transfer switches for selectively feeding power from one of two input lines to a load.
2. Background Information
Transfer switches are known in the art. See, for example, U.S. Pat. No. 5,397,868.
Transfer switches operate, for example, to transfer a power-consuming load from a circuit with a normal power supply to a circuit with an auxiliary power supply. Applications for transfer switches include stand-by applications, among others, in which the auxiliary power supply stands-by if the normal power supply should fail.
A transfer switch typically comprises a pair of circuit interrupters combined with a drive input and a linkage system. The preferred types of circuit interrupters have been molded-case switches and molded-case circuit breakers because these types are commercially available in a wide array of sizes and are relatively economical compared to other options. The preferred type of drive input depends on the application for the transfer switch. Usually motors are preferred, but at other times there is a clear preference for manually operated mechanisms.
In most residential and commercial buildings, the electrical wiring is only fed by a utility power source. In order to have a backup power source, such as a generator or inverter, it is necessary to provide a separate electrical back-up panel and, also, to re-wire the original panel. The cost of rewiring and the separate backup panel is great.
Accordingly, there is room for improvement in transfer switches.